We found this long piece of steel for our tool. Drill a hole
through the Center and install a bolt. Very simple and very
strong. |
If you're playing around with vintage bikes, you're going to run into
some puzzling moments when it comes time to figure out what springs to
use. After all, springs do wear out with the years, or if you're heavier
than the previous owner, you might simply need a stouter spring.
But, how can you tell what the actual rate of the spring is? Chances
are 10 to 1 that that the color coding has long since worn off, and even
if it was there, where are you going to find the coding information?
We devised a method for determining all of the spring rates of our
springs and it's so simple, it's ridiculous.
When a spring is made, the poundage is pounds per inch unless it's a
progressive spring; then the rate is slightly different. All you have to
do is compress the spring one inch when it's sitting on a scale and the
spring rate is shown right on the scale.
In order to do this, you need to steal the bathroom scale for a few
minutes. Grab a strong piece of metal about three feet long. If you don't
have a piece of steel that long, use an old two by four, or the closest
thing you have. That's the beauty of this whole thing; anything that's
long enough and strong enough will work.
Find a place to lever against and set-up your testing station.
Even the bumper of a car will work. |
Right at mid point, drill a hole or pound a big nail through. All this
does is keep the spring from flying off and killing a spectator. If you
use the steel bar, place a nut and bolt through the hole.
Take the scale and your new tool out to somewhere where you can hook
one end of the lever and push down. We used the edge of the fence in the
Sieman driveway.
Place the spring in the center of the scale and compress it one inch.
Hold a measuring tape beside the bar and push down until the thing travels
one inch. Take a quick look at the scale and read how stiff the spring is.
We tested this method with springs ranging from 70-145 pounders and
each time the readings were the same. As long as you compress the spring
only one inch, the readings will be accurate. If done properly, the value
of the springs will be known.
For a test, take a new set of springs that you know the rate and check
them. You'll be surprised to find they vary slightly, even if they haven't
been run.
Set the measuring tape up against the spring and... | 
? push down one inch. The scale tells the story. |
